ISSN 1004-4140
CN 11-3017/P

2019 Vol. 28, No. 6

CT Theory
In-situ Geotechnical CT and Its Key Technologies
ZHU Kairan, WANG Bo, WU Xiaomeng, GAO Jianshen
2019, 28(6): 641-652. doi: 10.15953/j.1004-4140.2019.28.06.01
Abstract(367) PDF(12)
The current application of industrial X-ray CT technology to observe the internal microstructure and mechanical properties of geotechnical soil has become a hot topic in engineering geology. However, the "large, heavy, dangerous, expensive" of the existing CT technology limits the field application capability, and the conventional geotechnical engineering survey method has the problem of losing or destroying the original geological information. This paper proposes the concept of in-situ CT technology and points out its key technologies in the application of geotechnical engineering. Based on the ultra-small cold cathode pulsed X-ray tube and imaging equipment, the in-situ CT experimental platform was built. The experimental results show that the method can realize in-situ digital sampling and CT rapid reconstruction. On this basis, the key points and key technologies of the follow-up research are clearly defined, including the new theory and new method of 2D/3D CT rapid reconstruction, and the analysis of the relationship between CT reconstructed image and geotechnical particle characteristics, and the local fine structure reconstruction algorithm, and the development of in-situ core 3D microstructure model. 3D printing technology will be combined to prepare the original position rock soil quasi-samples used to study the mechanical properties. A time-space four-dimensional geotechnical engineering measurement database will be established, and artificial intelligence algorithms were introduced to form a feedback evaluation system with learning and prediction. It is of great scientific significance to enrich existing geotechnical engineering survey methods and improve in-situ CT technology.
Study on Evaluation Method of Radiation Dose of Patients in TACE of IVR-CT
LIU Wangyang, SUN Cunjie, ZHAO Honglan, WANG Xiuling
2019, 28(6): 653-658. doi: 10.15953/j.1004-4140.2019.28.06.02
Objective: To establish the conversion formula between the Entrance Surface Dose (ESD) of the patient in the TACE treatment and the Dose Index (DI) from equipment. Methods: ESDs were measured from 50 patients who received TACE (37 Males, 13 Females; (70.3±6.8) years old) by placing fluorescent glass dosimeters on the skin surface. ESDs were measured in three locations, including the dorsal surface of the lesion, the scan field of CT and cone beam CT (CBCT). The total ESD, ESD in each CT scan and CBCT scan were measured, respectively. AXIOM Artis dTA/i-CT (Siemens) was used as the equipment of IVR-CT. The relationship between perspective DI and perspective ESD were explored. Results: The conversion formula between ESD and DI is established as: ESD=[(0.697×CTDI+7.175)×number of CT scans]+[0.384×CBCT DI-5.472]+[0.567×perspective DI -9.248]. Conclusions: DI and ESD have a good linear correlation. We can use the conversion to formulate ESD in this study.
Random Noise Simulation Method for Seismic Exploration Based on Typical Decomposition
LI Guihua, WANG Jingqi, XU Yun, ZHANG Wenbo, WANG Shulin
2019, 28(6): 659-667. doi: 10.15953/j.1004-4140.2019.28.06.03
Abstract(353) PDF(13)
With the development of mineral resources exploration, the seismic exploration and acquisition environment is more and more complex, and the received reflection seismic records often contain a lot of interference, which results in low signal-to-noise ratio, complex appearance and difficult to distinguish the effective information of field seismic data, which makes it difficult to extract and utilize the effective information in seismic records. Traditional numerical simulation records generally do not have a random interference noise background containing various causes. Although the processing effect of theoretical records is good, it is difficult to process the actual seismic data with low signal-to-noise ratio. Up to now, there are few forming theories for seismic random noise simulation methods, and there are some idealizations and limitations for the understanding of random noise characteristics of seismic exploration. In noise simulation, many studies add white noise which can be generally eliminated in subsequent superposition processing, and cannot be close to the actual data processing. Based on the classical decomposition theory of random functions and Marmousi model records, the additive random interference is calculated according to the coherence characteristics of the CMP gathers, which is more similar to the interference background of actual seismic data because of its similar coherence with CMP gathers records. This method can guide the design of field observation system for seismic exploration, post-processing and interpretation of seismic data.
Medical Imaging and Image Processing
Relationship between MRI Performance and Vascular Score of MRA in Adult Moyamoya Disease
LIANG Zhenhua, HE Weihong, HUANG Yaoqu, MA Fuqiang, LI Junhong
2019, 28(6): 669-675. doi: 10.15953/j.1004-4140.2019.28.06.04
Objective: To analyze the relationship between MRI and vascular score of MRA in adult Moyamoya disease (MMD), and to provide a theoretical basis for the clinical intervention of MMD. Methods: Analyze the clinical data of 50 adult patients with MMD performed by MRI and MRA. According to the Houkin`s rating method, MRA was performed on each side of the cerebral hemisphere, and the number of Moyamoya vessels (MMV) was also scored. The correlations between brain MRI manifestations (cerebral hemorrhage, cerebral ischemia, cerebral softening and brain atrophy) and MRA classification and MMV score were evaluated. Results: There were significant differences in cerebral hemorrhage and cerebral ischemia between different MRA classifications (χ2=13.04,P=0.005;χ2=8.21,P=0.04). The incidence of cerebral hemorrhage in patients with MRA grade II and III is higher, and the incidence of acute cerebral infarction in patients with grade I and IV is higher. There were significant differences in cerebral hemorrhage and cerebral softening between different MMV scores (χ2=24.79,P<0.001;χ2=11.42,P=0.02). The incidence of cerebral hemorrhage in patients with MMV scores 4, 5 points was higher, and the incidence of cerebral softening was higher with 1, 2 points. Conclusion: The MRA classification and the formation of MMV suggest the occurrence of cerebrovascular events in MMD to some extent, and preliminarily predict the possibility of cerebrovascular events, which can provide guidance for clinical prevention of cerebrovascular events in MMD.
A Predicting Model to Estimate the Probability of Malignancy in Solitary Pulmonary Nodules Basing on CT Images
YI Qinqin, ZHOU Zhou, HUANG Guoxin
2019, 28(6): 677-683. doi: 10.15953/j.1004-4140.2019.28.06.05
Objective: To establish a predicting model using multivariate logistic regression analysis for estimating the probability of malignancy in solitary pulmonary nodules, and to compare our model with Mayo model and Brock model. Methods: From January 2015 to December 2017, 319 patients with SPNs identified by histopathology in Shenzhen peoples' hospital were analyzed retrospectively. Among 319 cases, 229 patients were in modeling group (group A), and 90 patients were in validating group (group B). We analyzed gender, age, diameter, smoking history, spiculation, upper location, unclear border, lobulation, vacuole sign, vessel convergence sign, pleural indentation, ground glass opacity and calcification in patients of group A, selected independent influencing factors by univariate analysis and multivariate logistic regression analysis and established a predicting model. Our model was verified with the date of group B, and was compared with Mayo model and Brock model. Results: The age, diameter, upper location, unclear border, lobulation, vacuole sign, vessel convergence sign, pleural indentation, and ground glass opacity were shown statistically significance between malignant and benign SPNs in univariate analysis (P<0.05). The spiculation, unclear border, lobulation, and ground glass opacity were independent influencing factors in multivariate logistic regression analysis. When group B data was substituted into the established formula, the area under the ROC curve was 0.894, sensitivity was 91.3%, specificity was 77.3%, positive likely ratio was 4.02, negative likely ratio was 0.11, positive predictive value was 80.8%, negative predictive was 89.5%. The difference between our model and Mayo model was statistically significant (P=0.0049). The difference between our model and Brock model was not statistically significant (P=0.79). Conclusion: The spiculation, unclear border, lobulation, and ground glass opacity are independent influencing factors between benign and malignant solitary pulmonary nodules. This logistic regression equation has favorable effective functions for the diagnosis of SPNs. For patients in this study, our model is better than Mayo model, and is same as Brock model.
Preliminary Study on Differentiating Pleomorphic Adenoma and Malignant Tumors of the Parotid Gland by Texture Analysis of Non-Enhanced CT Images
REN Sitong, LI Xiaohu, LIU Bin, LI Lulu, LI Zhijie, HU Chong, SHU Jingwei
2019, 28(6): 685-691. doi: 10.15953/j.1004-4140.2019.28.06.06

Objective: To evaluate the possibility of texture analysis on non-enhanced CT images for differentiating pleomorphic adenoma and malignant tumors of the parotid gland. Materials and Methods: 45 cases of parotid pleomorphic adenoma and 12 cases of primary malignant tumor of the parotid gland confirmed by pathology were included in this retrospective study. Texture analysis software was used to delineate region of interest (ROI) on the lesions of these non-enhanced CT images, and obtained 18 texture parameters. Nonparametric test was used to statistically analyze the texture parameters of parotid pleomorphic adenomas and malignant tumors, and the ROC curve was used to evaluate the diagnostic effect of parameters with statistical difference. Results: Among the 18 different CT texture parameters generated on these non-enhanced CT images, 10 texture parameters were statistically significant between the PA group and the MT group (P<0.05). Among them, Median Intensity, Mean Value Voxel Value Sum, RMS, Mean Deviation have higher diagnostic efficacies, the AUCs are all greater than 0.8. Conclusion: Texture analysis of CT plain scan images can be used to identify parotid pleomorphic adenomas and parotid malignancies.

Spectral CT
Application of Energy Spectral CT in the Diagnosis of Acute Pulmonary Embolism and Evaluation of Pulmonary Perfusion Changes
YAO Biao, LI Xiaofeng, LIU Caiyun, SHI Yan
2019, 28(6): 693-699. doi: 10.15953/j.1004-4140.2019.28.06.07
Objective: To investigate the value of energy spectral CT in the diagnosis of acute pulmonary embolism and pulmonary perfusion changes. Methods: A retrospective analysis of 43 cases of suspected acute pulmonary embolism from November 2017 to July 2019, all patients with suspected acute pulmonary embolism underwent enhanced spectrum scanning, and the original data images reconstructed pulmonary angiography images and iodine-based substances at the workstation. Observe and record the location and number of pulmonary emboli; analyze the location and number of intrapulmonary perfusion reduction zone in the iodine-based substance map, and measure the iodine value and CT value of the intra-poor hypoperfusion zone, and measure the normal lung of the same level or adjacent level Substantial iodine value and CT value. The chi-square test was used to compare the number of emboli detected by the mixed energy image with the best single-energy image. The two-sample rank sum test was used to compare the iodine value and CT value between the perfusion reduction zone and the normal zone. RESULTS: A total of 12 patients with pulmonary embolism were diagnosed. A total of 256 emboli were found by mixed energy imaging. Among them, 22 were central emboli (pulmonary trunk and lobes), and peripheral type (pulmonary and lung sub-emboli) 234. There were 58 fully occluded emboli and 198 non-completely occluded emboli. A total of 273 emboli were found by the best single-energy image observation, including 22 central emboli (pulmonary trunk and lobes) and 251 peripheral (pulmonary and pulmonary emboli); fully occluded embolus 74, 199 non-completely occluded emboli. The best single-energy image had a higher detection rate than the mixed energy image in the diagnosis of peripheral and fully occluded emboli, but the difference was not statistically significant (P>0.05). The intrapulmonary perfusion reduction area was 42, the perfusion reduction area ((2.70±1.81) 100ug/mm3, (-829±45.94) HU) and the normal area lung field ((17.78±3.29) 100ug/mm3, (-741±34.34) HU) iodine value, CT value for comparison, the difference was statistically significant (P<0.05). Conclusion: Energy spectral CT can be used for qualitative and local diagnosis of pulmonary embolism. Iodine-based substance map can evaluate pulmonary blood perfusion changes and provide information for evaluating pulmonary embolism.
Clinical Value of Spectral CT Imaging with Rapid Voltage Switching for Pulmonary Nodules
CHEN Mai-Lin, SUN Ying-Shi
2019, 28(6): 701-708. doi: 10.15953/j.1004-4140.2019.28.06.08
Abstract(318) PDF(10)
Current studies have confirmed that spectral CT imaging can be used to evaluate the nature of the lesion. For pulmonary nodules, spectral CT imaging can help to differentiate benign and malignant pulmonary nodules. For lung cancer, spectral CT imaging can also provide information about qualitative, staging and therapeutic effect. This article reviews the clinical application of spectral CT technology for pulmonary nodules, including spectral CT scanning technology of pulmonary nodules, differential diagnosis of pulmonary nodules, staging of lung cancer, correlation with clinical indicators and its application in monitoring curative effect.
Medical CT
The Study of Optimization for Scanning Speed with Ultra Low Dose Contrast Agent Applied and Low Dose of Radiation in Cranio-cervical CTA for Common Weight Cases
ZHU Zhenhua, SHI Hao, YANG Guangjie, LI Haiwen, LV Yingqiang
2019, 28(6): 709-719. doi: 10.15953/j.1004-4140.2019.28.06.09
Objective: To study the feasibility of cranio-cervical CTA by dual source CT with low-dose radiation and contrast agent (26~32mL) for common weight (79.4±14.5kg) and BMI (21kg/m22) cases. Methods: 80 cases of cranio-cervical CTA were randomly divided into experimental group (group A) and control group (group B), with 40 cases in each group. The parameters such as trigger threshold, pitch and rotation time of group A were optimized. Then the image quality and the radiation dose produced by Head Angio sequence were compared between the two groups. Results: the objective evaluation indexes of the other segments except the bilateral internal carotid artery in group A were lower than that of group B, the difference between the two groups was statistically significantand (P<0.05). The dosage of contrast agent (29.07±2.05) mL and radiation dose were lower than that of group B,the differences between the two groups were statistically significantand (P<0.05). The subjective evaluation of the contrast agent concentration in the right subclavian vein and the cephalic vein was better than that of group B, the differences between the two groups were statistically significantand (P<0.05). The subjective evaluation of arterial images between the two groups were not statistically significant (P>0.05). Conclusion: Dual source CT can be used for cranio-cervical CTA with low radiation dose and ultra low contrast agent for common weight cases.
CTA and MRI Evaluation of Asymptomatic Carotid Artery Stenosis and Its Clinical Association
WANG Bihao, WANG Baoping, ZHAO Lei, DUAN Yandong, GUO Ping, JIAO Xiangfeng
2019, 28(6): 721-730. doi: 10.15953/j.1004-4140.2019.28.06.10
objective: To retrospectively analyze the imaging findings of asymptomatic carotid artery stenosis patients to evaluate the occurrence and development of atherosclerotic disease and its clinical correlation. Methods: A retrospective analysis of 81 patients with asymptomatic carotid artery stenosis with head and neck CTA was conducted to evaluate the image quality and the properties of atherosclerotic plaques, and to calculate the stenosis degree. Pearson correlation test was performed for degree of carotid artery stenosis and coronary artery stenosis, degree of carotid artery stenosis and white matter lesions, degree of carotid artery stenosis and coronary artery ACC/AHA score. According to whether the degree of total internal carotid artery stenosis is >50% or not, it can be divided into two groups: asymptomatic carotid artery stenosis group and control group. Independent sample t test was conducted for the degree of coronary artery stenosis between the two groups. The results of head MRI were scored, and the t test between the two groups was performed. The incidence of atherosclerosis in aortic arch in asymptomatic carotid artery stenosis group and control group was evaluated by chi-sqaure test. Results: The degree of carotid artery stenosis was positively correlated with the degree of coronary artery stenosis, the degree of carotid artery stenosis with the degree of white matter lesion, and the degree of carotid artery stenosis with the degree of coronary artery ACC/AHA score compared with the control group, there were statistically significant differences in the t-test results of asymptomatic carotid artery stenosis in patients with coronary artery plaque formation (P<0.05). The corresponding head MRI findings in the asymptomatic carotid artery stenosis group showed lacunar cerebral infarction and white matter lesion were heavier than those in the control group, and there were significant statistical differences in t test results between the two groups (P<0.05).The incidence rate of atherosclerosis in the aortic arch was statistically significant by four-grid chi-square test (P<0.05). Conclusion: Atherosclerosis is a systemic disease. The degree of total internal carotid artery stenosis is associated with the development of coronary atherosclerosis and aortic atherosclerosis. The degree of coronary artery stenosis is related to the degree of stroke and the corresponding total internal carotid artery stenosis.
Comparative Analysis of MRI Findings and Pathology in Acoustic Neuroma
FANG Fang, HU Shaoping
2019, 28(6): 731-738. doi: 10.15953/j.1004-4140.2019.28.06.11
Objective: Comparative analysis of the correlation between MRI findings and pathological features of acoustic neuroma for the improvement of the diagnostic imaging level of the disease. Methods: Retrospective analysis of 24 cases of acoustic neuroma MRI findings confirmed by surgery and pathology, including morphology, size, signal, diffusion limitation and enhanced scanning enhancement, compared with pathological features. Results: There were 18 solid cystic lesions of acoustic neuroma in 24 cases, 14 cases with internal auditory canal enlargement, 2 cases with Hemorrhage, cerebral tissue edema around 14 lesions, 1 case of solid part was slightly diffuse restricted, enhanced scanning of the solid part of the moderate-obvious strengthening, cystic part without strengthening. The pathological features are the coexistence of Antoni A-type cells and Antoni B-type cells. 4 cases of solid lesions all with internal auditory canal enlargement, 1 case with hemorrhage, 2 cases with peripheral brain tissue edema, 2 cases with mild diffusion limitation, and enhanced scans are moderately-apparently enhanced. Pathological features: mainly rich Antoni A spindle cells.2 cases of cystic enhanced scanning wall enhancement, 1 case with internal auditory canal enlargement, 1 case with peripheral brain tissue edema; 2 cases with capsule, there were no hemorrhagic components and diffuse restricted signs in the lesions. Pathological features: It is mainly composed of Antoni type B cells, and the wall component is Antoni type A cells.Conclusion: MRI findings of acoustic neuroma reflect the pathological features to a certain extent, and MRI examination is helpful for its diagnosis and differential diagnosis.
CT Feature Analysis of Common Benign Tumors of Parotid Gland
2019, 28(6): 739-745. doi: 10.15953/j.1004-4140.2019.28.06.12
Objective: To analyze the clinical and CT manifestations of common benign parotid gland tumors, so as to improve the preoperative diagnosis accuracy. Methods: Clinical data and CT imaging data of 45 patients with parotid gland benign tumor confirmed by surgery and pathology were retrospectively analyzed. Results: Among the 45 patients, there were 24 cases of pleomorphic adenoma (all single), 6 cases of basal cell adenoma (all single), 15 cases of adenoma (5 cases of single occurrence, 10 cases of multiple occurrence, 5 cases of bilateral multiple occurrence). Ten patients with adenocarcinoma had a long history of smoking. Pleomorphic adenoma presents progressive enhancement. Basal-cell adenoma showed significant enhancement in arterial stage and venous stage, and decreased slightly in venous stage compared with arterial stage. Adenocarcinoma presents as "fast in, fast out", and may have vascular border signs; 3 patients had different enhancement methods, and the difference of enhancement was statistically significant (P<0.05). Conclusion: The common benign tumors of parotid gland have some CT features, which is helpful to improve the preoperative diagnosis accuracy.
Clinical Practice of CT Coronary Angiography in Acute Chest Pain: A Review
2019, 28(6): 747-752. doi: 10.15953/j.1004-4140.2019.28.06.13
Acute chest pain is an important public health problem, which can cause high medical costs and significantly affect people's health. Acute coronary syndrome (ACS) is the main cause of vascular lesions of acute chest pain. Radiology can quickly and effectively diagnose vascular lesions. This article reviews the clinical practice of CT coronary angiography in acute chest pain.
The Research Progress of CT in Evaluating the Course of Cirrhosis
LIU Peiyao, HAO Fene, LIU Aishi, ZHAO Lei
2019, 28(6): 753-761. doi: 10.15953/j.1004-4140.2019.28.06.14
The non-invasive assessment of cirrhosis has important clinical significance, there are a variety of imaging examination techniques and methods can be used to evaluate cirrhosis, this paper, combined with relevant literature at home and abroad, introduced the CT in the evaluation of cirrhosis in the course of several methods, functions and evaluation effects, and summarized its research progress and clinical application prospects.